Steven PembertonThe Sapir-Whorf Hypothesis postulates a link between thought and language: if you havenât got a word for a concept, you canât think about it; if you donât think about it, you wonât invent a word for it. The term âWeb 2.0â is a case in point. It was invented by a book publisher as a term to build a series of conferences around, and conceptualises the idea of Web sites that gain value by their users adding data to them. But the concept existed before the term: Ebay was already Web 2.0 in the era of Web 1.0. But now we have the term we can talk about it, and it becomes a structure in our minds, and in this case a movement has built up around it.There are inherent dangers for users of Web 2.0. For a start, by putting a lot of work into a Web site, you commit yourself to it, and lock yourself into their data formats. This is similar to data lock-in when you use a proprietary program. You commit yourself and lock yourself in. Moving comes at great cost. This was one of the justifications for creating the eXtended Markup Language (XML): it reduces the possibility of data lock-in â having a standard representation for data helps using the same data in different ways too.As an example, if you commit to a particular photo-sharing Web site, you upload thousands of photos, tagging extensively, and then a better site comes along. What do you do? How about if the site you have chosen closes down (as has happened with some Web 2.0 music sites): all your work is lost. How do you decide which social networking site to join? Do you join several and repeat the work? How about geneology sites, and school-friend sites? These are all examples of Metcalfâs law, which postulates that the value of a network is proportional to the square of the number of nodes in the network. Simple maths shows that if you split a network into two, its value is halved. This is why it is good that there is a single email network, and bad that there are many instant messenger networks. It is why it is good that there is only one World Wide Web.Web 2.0 partitions the Web into a number of topical sub-Webs, and locks you in, thereby reducing the value of the network as a whole.So does this mean that user contributed content is a Bad Thing? Not at all, it is the method of delivery and storage that is wrong. The future lies in better aggregators.